The present disclosure relates to a liquid crystal display apparatus having a sub-pixel structure made up of sub-pixels of four colors of red (R), green (G), blue (B), and white (W), for example.
In recent years, as a display for flat-screen televisions and portable terminals, an active-matrix liquid crystal display (LCD) apparatus in which TFT (Thin Film Transistor) is disposed in each pixel is often used. In such a liquid crystal display apparatus, generally, a video signal is line-sequentially written to a subsidiary capacitive device and a liquid crystal device of each pixel from the upper portion to the lower portion of the screen, thereby driving each pixel.
In the past, in order to lower power consumption of a liquid crystal display apparatus during video display, configurations in which each of pixels in a liquid crystal display panel includes sub-pixels of four colors (see Japanese Examined Patent Application Publication No. Hei 4-54207, Japanese Unexamined Patent Application Publication No. Hei 04-355722, and Japanese Patent No. 4354491, for example) have been proposed. Here, the sub-pixels of four colors include sub-pixels of three colors, red (R), green (G), blue (B), and a sub-pixel of a color higher in luminance than the three colors (Z; white (W) or yellow (Y), for example). When a video display is carried out using video signals for such sub-pixels of four colors, luminance efficiency can be enhanced in comparison with the case where a video display is carried out by supplying video signals for three colors to each pixel having a known sub-pixel structure of three colors of R, G, and B.
Meanwhile, in Japanese Patent No. 4354491, a liquid crystal display apparatus in which luminance of a back light is actively (dynamically) controlled (dimming processing is carried out) according to a video to be displayed (according to a signal level of a video signal) has been proposed. When using this method, it is possible to realize lower power consumption and expansion of dynamic range while keeping a display luminance.